Databases have played a critical role in business areas such as banking and airline reservations for many years. These two lines of business illustrate how critical availability of a database can be. If a bank cannot process customer transactions (deposits, payments, transfers, etc.) because of a computer system failure, a customer may be unable to accomplish its business. Likewise, if an airline is unable to book reservations, customers may be lost and its planes may fly empty. Therefore, database availability is critical.
There are generally two components to backing-up a transaction oriented database. One component is creating a backup copy of the files that comprise the database, and the second component is tracking updates made to the database. Thus, for a full recovery of a database, the most recent backup copies of the database files are reloaded, and the database updates made subsequent to the backup of the database files must be applied to the reloaded files. The process of backing-up database files is sometimes referred to as "dumping" the database, and the process of logging status information and database updates is sometimes referred to as "auditing." The database backup files are "database dumps" and the file to which update information is logged is the "audit file."
In one prior system, for example, the Integrated Recovery Utility from Unisys Corporation, information related to the database dumps and audit file backups was maintained in a history file. The history file included the tape identifiers of the tapes on which the dumps and backups were stored, the times of the dumps, and the ranges of audit records stored on respective tapes.
The history file freed the database administrator from having to manually track the tapes and times associated with the database dumps and audit backups. However, simultaneous database dumping and audit archiving were not permitted in order to prevent corruption to the history file. Furthermore, redundant copies of archived audit information required a separate administrator-maintained mechanism (in addition to the history file) for tracking the locations of additional audit archives.
A system and method that addresses the aforementioned problems, as well as other related problems, is therefore desirable.